I am currently trying to test the effectiveness of various thermal compounds (TIMs) on cpu processors. I am currently trying to find the thinnest thermal probe/thermocouple I can find for this project.
My current idea is that I could place one prob ontop of the CPU and then apply the thermal compound. I would then place another probe and then attach the heatsink.

From there I could measure the heatchange and calculate the thermal conductivity of the product.

I have seen many techniques that would first take the processor and mill out a canal in the casing of the processor to place the thermocouple inside, but I am hoping that there is another way